<script>
  let mark = "你好";

  // $: dbmark = mark + "***" + mark;

  // const getData = () => {
  //   console.log(mark);
  //   mark += "happpy"
  // };

  setTimeout(()=>{
    mark = 'hello'
  },1000)
</script>

<textarea bind:value={mark}></textarea>

<div>{mark}</div>
<!-- <div>{dbmark}</div> -->

<!-- <button onclick={getData}> 获取值</button> -->
